Gas Chromatography‐Mass Spectrometry Analysis and Neuropharmacological Evaluation of Aqueous Extract of Aerial Parts of Caralluma dalzielii N E Brown

Abstract

IntroductionCaralluma dalzielli (Asclepiadiaceae) is a succulent perennial plant that is widely distributed across the Sahel region of West Africa. Decoctions from the plant are used traditionally for treating infertility, epilepsy and neurological diseases. The aim of the present study was to evaluate some neurological effects of aqueous extract of aerial parts of Caralluma dalzielii (APCD) in mice and to analyse its components through Gas chromatography‐mass spectrometry (GC‐MS).Materials and methodsThe effect of the APCD (100, 200 and 400 mg/kg p.o) on motor coordination, sedation and anxiety in mice were assessed using three models, namely, beam walk assay, staircase test and hole‐board test. Its anticonvulsant activity was assessed in pentylenetetrazole (PTZ) and strychnine (STN)‐induced seizures in mice. Beam walk assay measured the number of foot slips of the mice, staircase test, measured the number of rearing for each mouse over a 5‐min period while the hole‐board test measured the number of head dips of the mice during a 5‐min period. In the anticonvulsant study, the onset and duration of seizures were recorded. Phytochemical screening was carried out according to standard procedures. APCD was subjected to further analysis using GC‐MS to identify its major components.ResultsAn increase in the number of foot slips is regarded as having peripheral muscle relaxant and sedative activities, however, APCD at all doses showed no significant increase in the number of foot slips. Increase in the number of rearing is a characteristic of anxiety. APCD at all doses significantly (p<0.05) reduced the number of rearing suggesting anxiolytic activity. The behavioural episode of head dipping was used for assessing anxiolytic activity. Increase in the number of head dips described anxiolysis. The extract showed a significant (p<0.05) increase the number of head dips at all dose levels. Pre‐treatment of mice with APCD produced a dose‐dependent protection against PTZ‐induced seizures with 100% protection at the highest dose of APCD. APCD also significantly (p<0.05) increased the latency/onset of myoclonic jerks and reduced the duration of tonic seizures dose dependently. In STN‐induced seizure, APCD significantly (p<0.05) prolonged the latency of tonic seizure and increased the survival time before death in a dose dependent manner. Phytochemical analysis of the extract showed the presence of alkaloids, flavonoids, tannins, saponins, steroids, cardiac glycosides and phenols. GC‐MS analysis revealed 85 compounds of which the major ones were Heptadecene (6.99%), Octadecene (6.83%), 2‐Amino‐5‐methylbenzoic acid (5.17%), 1‐Butoxy‐2,4‐dimethyl‐2‐pentene (4.97%), Benzene propanoic acid (4.89%), Hexadecanoic acid (3.94%), 2,4‐Di‐tert‐butylphenol (3.233%) and 1‐Tetradecanol (2.16%).ConclusionAPCD possesses neuropharmacological properties with anxiolytic and anticonvulsant activities but without prominent effect on motor coordination. The presence of various phytochemical constituents may be responsible. This report validates the ethnomedicinal use of the plant for the treatment of neurological diseases.